our 8 month old lab loved his crate for six months and then one day in march decided he hated it and now wont go near it without screaming, is this a phase or did we genuinely break something

Gus is an 8 month old yellow lab, came home at 9 weeks, was crate trained from day one and was honestly the dream case study. He went in willingly for naps by week three, slept through the night in there by month two, would go in on his own when he wanted quiet time. We were the smug puppy parents who told friends crate training was easy and you just had to be consistent. That smugness lasted exactly until march 14th when something flipped and he started refusing to enter the crate at bedtime, then started crying for two hours straight when crated during the day, and now (3 weeks later) he physically braces against the doorway and screams if i even try to walk him toward it.

Some context on what changed and what didnt. Nothing significant in his environment, we did not move, we did not change his schedule, no new pets, no traumatic event we are aware of. He turned 8 months old around that time which is the only obvious variable. He had his neuter scheduled for april which we have now postponed because we did not want to add another stress on top of this. He still loves the room the crate is in, sleeps next to it (with the door open) on his bed, just refuses to go in. He also started two other adolescent behaviors around the same time: counter surfing when he had never shown interest before, and pulling hard on leash when he had loose leash walked nicely for months.

What we have tried that has not worked. Going back to basics with treats in the crate (he eats them and leaves), feeding meals in the crate (he eats the meal halfway and then refuses to finish if i try to close the door, eventually we just stopped closing it), making the crate "fun" with new toys (he ignores them), letting him sleep loose in our bedroom instead and seeing if that resets things (it didnt, after a week loose at night the crate refusal during the day was worse not better). We have not tried medication or a behaviorist yet because we wanted to rule out a phase first.

My actual questions. one, is the 7 to 9 month crate regression a real developmental phase that we should expect to pass, or is it always pointing to something specific that needs addressing. two, did we make the situation worse by letting him sleep loose for that week, in retrospect that feels like a mistake but i was desperate. three, do we need to start over with crate training from total scratch like he is a puppy again, or is there a faster path back that respects he already knew how to do this. four, when do you bring in a CSAT or behaviorist vs trying to handle this yourself, we have the budget if needed but i dont want to throw money at it if waiting it out is the right call. five, the neuter is rescheduled for june, should we do it earlier to address the testosterone driven adolescent stuff or wait until the crate thing is resolved first. apologies for the wall of text, the smugness has been thoroughly knocked out of us at this point